Identify all Custom Elements used on a site.
Web Components are a collection of standards which are working their way through the W3C. One of these specs is called Custom Elements and gives you the ability to create your own HTML elements.
The idea behind this extension is to detect pages that are using it nowadays and show an icon in the address bar when it happens.
Source code available at: https://github.com/webcomponents/chrome-webcomponents-extension